Process of casting copper and copper alloys.



- Specific aiticuriof l'ietteirs i iatentr E PMI ET amat- Greet nfnofinss ast a wer gg g Mi I 'raeentease e. 15, 1908.

' iipplioationfiled i' rn 27 mos.- s im no. 314,086.

To all who'trt 'it my concern: I

Be it known that I, CONRAJi' GAursoH,

citizen of Germany, reslding at Munich, Bavaria, Germany, have inventedcertain new and useful Improvementsin) Processes for Casting CopperandCo per Alloys; andJI-do hereby declare the fo lowing to. be a full,clear, and exact description of the invention, such as will enableothers skilled in the art to In casting copper; or coppertalloys, the

presence of. oxid of [cop er tends {to prevent the attainment of a erectly eyen structure of the casting. Bot copper and its alloys remainhoneycombed to a certain extent.-

For the same reason it has hitherto been im'- possible to add copper orits. alloys to iron or.

steel in very large quantities or at least in ter metals eater hardnessor strength of resistance, t an that of the ordinary alloys. Q

In order to enable the addition of iron and the like, the assistance ofothenmetals such as zinc aluminium or nickel has beenrequisitioned,which actto a certain extent as carriers for the iron. c

According to the resent invention bicarbonate fnf soda is ad ed to theco per, which renders itpossible to add the d sired mixtures in muchgreater quantities, particularly to steel, the alloy as also the purecopper being entirely free from porosity and metal alloys beingobtained(bronzes) which possess exceptional powers of resistance against wearand mechanical influences.

1- Although it is known to add hydrates and alkalies to copper, this hashitherto always been effected simultaneously with an energetic feed ofoxygen and exclusively for the purpose of freeing the copper fromforeign metals and more particular y arsenic.

Thus the present process consists in adding to the metal-copper ormixtures of co 45 per, tin, old metal and iron steel or t e 'ke besidesthe usual .gaddition ,of phosphorus (which as is known tends to reducethe copper oxid formed) a" suitable quantity of bicarbonate of soda,without any special oxygen feed, a part being advantageously added rightat the commencement and a which it appertains to'*mal e and; use thecloser-to that of molten copper t substances heretofore employed, thesaid such large quantities, as to impart to the lat-- ,part after themetal has been melted. The

amount of bicarbonate of soda added may be from one to two fifths ercent. i

, The result of the ad ition of the bicarbonate-of soda is to render theuality of the molten metal much thinner, t at is to say -m'o're fluid,or less viscous, so thatit will homogeneouslp take u the mixtures ofsteel or other meta s adde in very considerable quantities, thusproducing alloys having eX-; ceptional hardness and of adensity.hitherto unsurpassed. v

' The effect of the addition of bicarbonateof soda, as far as the samecould be observed in the melting process appears to be that the samemelts at a temperature approaching an do the bicarbonate decomposing toform carbonate of soda and carbonic acid and causing the mass to foam,so that a art from the intimate mixture of the mo ten metal, the oxideand protoxidsfof co per are dissolved and thus ass out of the mo tenmass into the slag. T is'eflect of the bicarbonate of soda in dissolvingthe oxid is proved bythe presence of considerable quantities of oxid andprotoxid of copper in the slag floating on the cast metal. Theparticular advantage of bicarbonate of soda in the present case is'thatit does not easily melt and that conse uently its activity is developedjust when t e copper and other metals begin to melt. v

. I claim as my invention: v

1. In the process of casting copper and copper alloys, the ste whichconsists in adding to the metal bicarhonate of soda, substantially inthe absence of free carbon.

2. In the process of casting copper and cop er alloys, the step whichconsists in adding icarbonate of soda to the metal, then 95 melting thelatter and then adding more bicarbonate of soda.

3,111 the process of casting copper and copper alloys, the step whichconsists in adding during the melting process from one to two-fifthspercent. ,of bicarbonate of soda.

4. In the process of casting copper the step which consists in addingbicarbonate of In testimony whereof I hereunto affix my 4 sodiumtohmolten puref copper. h signature in the presence of two witnesses,

5. In t e process 'o casting 00 per t e i ste which consists in addingbicar onz te of v CONRAD GAUTSGH' 5 so( ium to ure cogper, then meltingthe lat- Witnesses;

ter, and t en ad mg more bicarbonate of i ULYssEs J. BYWATER,

sodium to the molten copper. I LOUIS F. MUELLER.

